Effect Of Rapid Thermal Annealing Research Articles

Nanoscopic analysis of rapid thermal annealing effects on InGaN grown over Si(111)

This study explores the impact of rapid thermal annealing (RTA) on InxGa1-xN grown over Si(111) by molecular beam epitaxy (MBE). Through X-ray diffraction (XRD) and reciprocal space map (RSM) characterization, notable shifts in diffraction peaks were observed post-annealing, suggesting alterations of the Indium content in the nanostructures. Morphological assessments using scanning electron microscopy (SEM) and atomic force microscopy (AFM) indicated that RTA could smooth the surface of the samples, though some instances of degradation were also noted. Energy-dispersive X-ray spectroscopy (EDS) showed further stoichiometric modification following annealing. Photoluminescence spectroscopy (PL) revealed notable shifts and increases in the intensity of the InxGa1-xN peaks, indicating the formation of regions with high Indium or Gallium concentration. The presence of these enriched regions was particularly evident from the peaks at around 540 nm and 433 nm, suggesting significant changes in the material's composition. Transmission electron microscopy combined with electron energy loss spectroscopy (TEM-EELS) corroborated the presence of In-rich and Ga-rich areas, affirming the phenomenon of Indium surface segregation. So, this study contributes to understanding the behavior of InxGa1-xN nanostructures under rapid thermal annealing, providing insights for advanced optoelectronic applications.

Effects of Rapid Heat Treatments on the Properties of Cu2O Thin Films Deposited at Room Temperature Using an Ammonia-Free SILAR Technique

We report herein the analysis of the properties of copper(I) oxide thin films deposited by an optimized ammonium-free successive ion layer adsorption and reaction (SILAR) technique. The Cu2O thin film deposition process was carried out at room temperature using copper acetate monohydrate, sodium citrate as complexing agent, and hydrogen peroxide as precursors of copper and oxygen ions, respectively. The harmless and easy-to-handle sodium citrate replaces the volatile NH4OH commonly employed as complexing agent in the SILAR technique for the deposition of metal oxide thin films. The optical, structural, morphological, and electrical properties of the as-deposited Cu2O thin films were studied as a function of the number of cycles during deposition, as well as their modifications produced by the effect of rapid thermal annealing (RTA) in vacuum in a temperature range of 200–250°C for 1 min, 3 min, and 5 min. The as-deposited thin films had cubic crystalline structure corresponding to the Cu2O phase as determined by x-ray diffraction (XRD), with a direct energy bandgap of 2.43–2.51 eV depending on the number of cycles, and electrical resistivity of the order of 103 Ω cm. The XRD and x-ray photoelectron spectroscopy (XPS) analysis of the Cu2O thin films treated by RTA demonstrated an increase of the crystal size with time and temperature of the RTA and reduction effects from Cu2+ to Cu1+ oxidation states. On the other hand, the RTA treatments also decreased their energy bandgap to 2.38 eV and electrical resistivity to 102 Ω cm. The high energy bandgap values of the Cu2O thin films were attributed to quantum confinement effects produced by their small crystal size in the range of 3.6–8.6 nm.Graphical

Effect of rapid thermal annealing on DC performance of Mg0.30Zn0.70O/Cd0.15Zn0.85O MOSHFET

This study focuses on a cost-effective method for fabrication of a metal oxide semiconductor-heterostructure field effect transistor (MOSHFET) based on MgZnO/CdZnO (MCO) using dual ion beam sputtering (DIBS), in contrast to the more expensive epitaxial growth system. The MOSHFETs developed in this research exhibit notable characteristics, such as a substantial two-dimensional electron gas (2DEG) transconductance (∼2.6 mS), a high ION/IOFF response ratio in the order of 108, and minimal gate leakage current. Furthermore, we explore the impact of rapid thermal annealing (RTA) on the drain current at various temperatures (600 °C and 800 °C). The results indicate a fourfold improvement in drain current compared to unannealed conditions, primarily attributed to reduced contact resistance and no degradation in term of MgZnO/CdZnO structure. Additionally, an analysis of post-RTA treatment under a nitrogen (N2) atmosphere on gate leakage current is presented. The investigation spans temperatures ranging from 400 °C to 800 °C, revealing that above 600 °C (gate leakage at 400 °C–600 °C is around ∼10−9 A), gate leakage in HFET is augmented by one order of magnitude (∼10−8 A) due to a phase change in the dielectric. These findings underscore the feasibility of DIBS-grown MCO MOSHFETs as an economical solution for the mass production of switching devices and sensors.

Metal-organic decomposed lanthanum cerium oxide thin films: A study of chemical and surface properties

Lanthanum cerium oxide thin films have been deposited on n-type (100) silicon wafers using the spin coating technique. The post-deposition annealing was performed over spin-coated films. The compositional studies were conducted by performing Fourier transform infrared spectroscopy, Energy dispersive X-ray spectroscopy, and X-ray diffraction. Ellipsometry was used to determine the thickness and atomic force microscopy was performed to understand the surface morphology of the deposited thin films. The effect of rapid thermal annealing at different temperatures over the structural and chemical properties of the LaCeO2 thin films was observed. The FTIR spectra show the formation of silicates at the interface of the oxide and semiconductor, while XRD results show that the films become crystalline with increased annealing temperature. The refractive index was observed to be reduced with an increase in the annealing temperature and a minor reduction in the physical thickness as per the sample standard deviation of 0.2981[Formula: see text]nm.

Effect of rapid thermal annealing on microstructure, mechanical and tribological properties of amorphous SiC hard coatings

Herein, a-SiC hard coatings were prepared by pulsed DC magnetron sputtering followed by rapid thermal annealing (RTA) at various temperatures. The influence of the RTA temperature on the coatings’ microstructure, mechanical and tribological properties was investigated. The results show that the surface morphology of a-SiC coatings almost unchanged and remains amorphous within 973 K annealing temperature. The content of sp3 first increases and then decreases with increasing annealing temperature, and reaches the maximum value at 773 K. The hardness (H) and elastic modulus (E) of the a-SiC coatings also increase firstly and then decrease due to the variation of sp3 content, while average friction coefficient decreases first and then increases. As the annealing temperature is 823 K, the maximal H, E of 25.02 GPa, 243.63 GPa are obtained. At 773 K annealing temperature, the minimum friction coefficient of 0.107 is realized, a-SiC coating exhibits higher H/E, H3/E2 and tribological properties.

Effects of rapid thermal annealing on deep-level defects and optical properties of n-type GaAsBi alloys grown by molecular beam epitaxy at low temperature

Effects of rapid thermal annealing on deep-level defects and optical properties of n-type GaAsBi alloys grown by molecular beam epitaxy at low temperature

Optical, morphological and electrical properties of rapid thermally annealed CoPc/n-Ge heterostructures for photodiode applications

Effect of rapid thermal annealing (RTA) temperature on electrical, morphological and optical properties of cobalt phthalocyanine (CoPc)/n-Ge heterostructures is investigated. UV–Vis measurements of as-deposited and annealed CoPc thin films show the presence of Q band transition at 618 nm and 690 nm absorption wavelength suggesting π-π* transitions. A phase transition is evidenced for the 300 °C annealed CoPc sample. Further, no degradation of Q band intensities is noticed which signifies highly stable CoPc thin films even after annealing at 400 °C. AFM measurements of CoPc thin film on Ge substrate reveal an increased RMS roughness with increased annealing temperature until 200 °C and further roughness was found to be decreased for the sample annealed at 300 °C. A clear change in the morphology of CoPc thin films is observed for the 300 °C annealed sample than 200 °C annealed sample which shows an evidence for the phase transition of CoPc thin films from α-phase to β-phase. This phase transition of CoPc thin films was also confirmed using XRD measurements. FESEM with EDS measurements were carried out for the as-deposited and annealed heterostructures. The surface topography of all the samples reveals a spherical-grained morphology and the grains seem to be highly dispersed in 400 °C annealed CoPc/Ge layers. The electrical and current transport mechanisms of the Au/CoPc/n-Ge heterostructure have been explored at different annealing temperatures by using I–V and C–V characteristics. Notably, the results reveal that superior barrier parameters are observed for the heterostructure annealed at 300 °C than as-deposited heterostructure. Rapid thermal annealing of the Au/CoPc/Ge heterostructure shows its promising applications in the areas of optoelectronic or photoresponsive devices.

Structural and optical properties of Cu implanted Ge thin films

Effects of rapid thermal annealing (RTA) on 100 keV Cu implanted germanium (Ge) thin films were studied in the present report. The Cu ion implantation into Ge films was carried out at different ion fluences 5 × 1015 and 1 × 1016 ions/cm2. Subsequently, the implanted samples were subjected to RTA at 600 °C. XRD and Raman results illustrate the amorphization of implanted films, whereas RTA results in crystallization. Crystallite size increases from 10.5 to 11.6 nm with fluence for RTA-treated samples. The bandgap of pristine film is 0.73 eV, which gets narrowed to 0.59 eV with an increase in ion fluence. RTA leads to increase in band gap up to 1.16 eV due to recovery of lattice damage and recrystallization of films. XPS analysis of RTA-treated implanted films reveals the presence of Ge, Ge suboxides, and Cu. The broad PL emission in the visible region signifies the possible use of Ge for optoelectronic applications.

Effect of rapid thermal annealing on the charge storage kinetics of conductive N-doped SnO2 thin film anodes for Li-ion batteries

This study focuses on the fabrication of a flexible thin film electrode composed of N-doped tin oxide (SnO2: N). The fabrication process involves sputtering SnO2 onto a Cu foil sheet using radio frequency (RF) magnetron sputtering, conducted under an N2 atmosphere. The deposited thin films are subsequently exposed to annealing treatment using rapid thermal annealing (RTA) at temperatures ranging from 200 to 400 °C. The primary objective of this study is to get an understanding of the effects of N-doping, annealing temperature on the growth of SnO2: N. as well as the influence of film thickness on the crystallographic state. We evaluate their thin-film anode performance for lithium-ion batteries (LIBs). The specific capacity of the as-deposited SnO2 thin films standing at 859 mAh g−1 when measured at 1 mA g−1. This enhanced capacity is attributed to the limited crystal growth in ultrathin SnO2, a factor that effectively combats electrode degradation while simultaneously improving the lithium-ion diffusion coefficient and electron kinetics of the electrode. However, the SnO2: N film that undergoes annealing at 400 °C demonstrates remarkable cyclic retention, reaching 82 %. This improvement is due to the enhanced electrical conductivity resulting from annealing, which prevents the aggregation of tin (Sn) and effectively accommodates the volume changes that occur in prolonged cycles. Additionally, this synchronized approach involving sputtering and RTA is proving to be a simple, efficient, and scalable method. It holds the potential to emerge as a valuable strategy to produce anode materials for lithium-ion batteries.

Mid-wave infrared photoluminescence from low-temperature-grown PbSe epitaxial films on GaAs after rapid thermal annealing

We investigate the beneficial effects of rapid thermal annealing on structure and photoluminescence of PbSe thin films on GaAs (001) grown below 150 °C, with a goal of low temperature integration for infrared optoelectronics. Thin films of PbSe deposited on GaAs by molecular beam epitaxy are epitaxial at these reduced growth temperatures, yet the films are highly defective with a mosaic grain structure with low angle and dendritic boundaries following coalescence. Remarkably, we find that rapid thermal annealing for as short as 180 s at temperatures between 300 and 425 °C in nitrogen ambient leads to extensive re-crystallization and transformation of these grain boundaries. The annealing at the same time dramatically improves the band edge luminescence at 3.7 μm from previously undetectable levels to nearly half as intense as our best conventionally grown PbSe films at 300 °C. We show using an analysis of laser pump-power dependent photoluminescence measurements that this dramatic improvement in the photoluminescence intensity is due to a reduction in the trap-assisted recombination. However, we find it much less correlated with improved structural parameters determined by x-ray diffraction rocking curves, thereby pointing to the importance of eliminating point defects over extended defects. Overall, the success of rapid thermal annealing in improving the luminescent properties of low growth temperature PbSe is a step toward the integration of PbSe infrared optoelectronics in low thermal budget, back end of line compatible fabrication processes.

Effect of Rapid Thermal Annealing on Si-Based Dielectric Films Grown by ICP-CVD.

Silicon nitride, silicon oxide, and silicon oxynitride thin films were deposited on the Si substrate by inductively coupled plasma chemical vapor deposition and annealed at 1100 °C for 3 min in an Ar environment. Silicon nitride and silicon oxide films deposited at ratios of the reactant flow rates of SiH4/N2 = 1.875 and SiH4/N2O = 3, respectively, were Si-rich, while Si excess for the oxynitride film (SiH4/N2/N2O = 3:2:2) was not found. Annealing resulted in a thickness decrease and structural transformation for SiOx and SiNx films. Nanocrystalline phases of Si as well as α- and β-Si3N4 were found in the annealed silicon nitride film. Compared to oxide and nitride films, the oxynitride film is the least susceptible to change during annealing. The relationship between the structure, composition, and optical properties of the Si-based films has been revealed. It has been shown that the calculated optical parameters (refractive index, extinction coefficient) reflect structural peculiarities of the as-deposited and annealed films.

Insightful studies of AuCu nanostructures deposited on Ti platform: Effect of rapid thermal annealing on photoelectrochemical activity supported by synchrotron radiation studies

In this work, we present the influence of annealing atmospheres during rapid thermal annealing (40 °C/s) on nanostructured Ti platforms modified by 10 nm layer of AuCu alloy obtained via magnetron sputtering. The AuCu/Ti platform annealed under hydrogen atmosphere exhibits the best photoelectrochemical activity under visible light, i.e. 27 times higher photocurrent than for pure Ti dimpled platform, and the lowest reflectance with minimum at ca. 750 nm. Synchrotron radiation studies allow for inspection in three zones, such as the upper (2–3 nm) and deeper (5–7 nm) surface layers as well as the bulk structure (12–15 nm). Taking into account hydrogenated AuCu/Ti platforms gold presence was confirmed in the upper and deeper surface layers as well as in bulk whereas AuxCuy nanoalloy only in the deeper layer. In the case of copper, Cu2O or Cu were distinguished in the upper and deeper surface layers, where Cu+1/Cutot ratio reaches 70 % in the upper layer and drops to about 40 % at a depth of 5–7 nm. Hydrogenation has a positive effect on photovoltaic performance by efficient acceptor–donor configuration of AuCu doping on/into TiO2 semiconductor showing its potential ability as photoanode in solar cells.

Structural characteristics and sensing capabilities of stacked Ti/Ni sensitive film for extended-gate field-effect transistor solid-state pH sensors

This study describes a straightforward approach for fabricating stacked Ti/Ni sensitive membranes on n+-type Si substrates using dc sputtering to build solid-state extended-gate field-effect transistor (EGFET) pH sensors. The effects of rapid thermal annealing (RTA) temperature (500–700 °C) and ambient (N2 or O2) on the structural characteristics of stacked Ti/Ni sensitive films were fully explored. We used X-ray photoelectron spectroscopy, secondary ion mass spectroscopy, X-ray diffraction, atomic force microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy to characterize the chemical compositions, element profiles, film structures, surface morphologies, film microstructures, and film compositions of the stacked Ti/Ni sensitive films. The relative structural characteristics of the stacked Ti/Ni sensitive films have a significant impact on their sensing capabilities. The most effective sensing performance, such as pH sensitivity, drift, and hysteresis, was achieved at an RTA temperature of 600 °C and in the presence of N2 gas among various RTA temperatures and annealing ambient. Due to its compact size and strong stability, the stacked Ti/Ni sensitive film shows great potential for use in future pH sensor and biosensor applications.

Investigation of deep defects and their effects on the properties of NiO/β-Ga2O3 heterojuncion diodes

In this study, the effect of rapid thermal annealing (RTA) on the electrical and optical properties of NiO/ β-Ga2O3 heterojunction diodes was investigated using capacitance-voltage, current-voltage, Deep Level Transient Spectroscopy (DLTS), Laplace DLTS, photoluminescence and micro-Raman spectroscopy techniques, and SILVACO-TCAD numerical simulator. The NiO is designed to be lowly-doped, allowing for the NiO full depletion at zero bias and the study of properties of β-Ga2O3 and its interface with NiO. Micro-Raman results revealed good agreement with the theoretical and experimental results reported in the literature. The photoluminescence intensity of the sample after RTA is five times higher than the fresh sample due to a rise in the density of gallium and oxygen vacancies (VGa + VO) in the annealed β-Ga2O3 samples. The current-voltage characteristics showed that annealed devices exhibited a lower ideality factor at room temperature and higher barrier height compared with fresh samples. The DLTS measurements demonstrated that the number of electrically active traps were different for the two samples. In particular, three and one electron traps were detected in fresh samples and annealed samples, respectively. SILVACO-TCAD was used to understand the distribution of the detected electron E2 trap (Ec-0.15 eV) in the fresh sample and the dominant transport mechanisms. A fairly good agreement between simulation and measurements was achieved considering a surface NiO acceptor density of about 1 × 1019 cm−3 and E2 trap depth into the surface of β-Ga2O3 layer of about 0.220 µm and the effect of the most observed Ec-0.75 eV trap level in β-Ga2O3. These results unveil comprehensive physics in NiO/β-Ga2O3heterojunction and suggest that RTA is an essential process for realizing high-performance NiO/β-Ga2O3devices.

Effect of substrate rotation and rapid thermal annealing on thermoelectric properties of Ag-doped Sb2Te3 thin films

In this work, homogeneous Ag-doped Sb2Te3 (AST) thin films were prepared using the rf magnetron sputtering technique. Thermoelectric properties of AST films have been investigated in terms of various substrate rotation speeds (20, 40, 60, and 80 rpm) and rapid post-thermal treatments at 250 oCin a vacuum. It was found that the thickness of AST films decreases with the increase in substrate rotation speeds. An Ag atomic composition slightly increases and the other Sb and Te atomic compositions slightly decrease with the increase of substrate speed rotations. The post-thermal treatment improved film crystallinity. Carrier scatterings at the grain boundaries tend to increase the resistivity and the Seebeck coefficient. The maximum power factor of 4.60 mW m−1K−2 (ρ = 19 μΩm, S = 298 μVK−1) is obtained in the AST thin films prepared with the substrate rotation speed of 60 rpm. The practical application of AST films was also reported via a thermoelectric module of five p-AST/n-Bi2Te3thin-film pairs with its achieved output power of 1.6 nW at ΔT = 20 K.

Regulation of structural, electrical and optical properties of Sb-doped SnO2 films prepared with different O2 flow rates by rapid thermal annealing

Effects of rapid thermal annealing (RTA) on the structure and photoelectric properties of Sb-doped SnO2 (ATO) films have not been systematically reported. In this study, ATO films were prepared by RF magnetron sputtering under different O2 flow rates (0, 15, 30 and 45 sccm), and then were subjected to RTA at different temperatures (400, 600 and 800 °C) in atmospheric environment. The results show that preferred orientations of ATO films changes from (101) to (110) crystal-plane and crystallite size increases with increasing O2 flow rate. RTA cannot change the films’ preferred orientation and crystallite size except for the film deposited in Ar atmosphere (0 sccm O2), but it can decrease the compressive stress in the films. The as-deposited and annealed films with low transmittance in visible light range (TVis) have obvious Raman scattering peak, and scattering peak of Eg vibration mode is stronger in the appearing Raman scattering peaks. Increasing O2 flow rate degrades electrically conductive properties of the films, increases TVis and makes optical band-gap (Eopt) first increase and then decrease. With increasing RTA temperature, the electrically conductive properties enhance and Eopt increases for the films deposited with all O2 flow rates, but TVis basically decreases for the films deposited with O2 flow rate of 15–45 sccm. Currently, the ATO film deposited at 15 sccm O2 and annealed at 600 °C has the best transparent conductive properties (the resistivity, sheet resistance, TVis and figure of merit are 2.09 × 10−3 Ω cm, 67 Ω/sq., 77.12%, and 1.11 × 10−3 Ω−1, respectively). In addition, element chemical states and point defects in the films were analyzed by XPS. Meanwhile, influence mechanisms of O2 flow rate and RTA on structure and properties of the films were discussed.

Effect of Rapid Thermal Annealing on Material, Electrical, and Sensing Characteristics of Ag-Doped CaTiO3-CuO Thin Film Carbon-Dioxide Gas Sensors

The effect of rapid thermal annealing (RTA) on CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> sensing characteristics of RF-sputtered and Ag-doped CaTiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -CuO thin films has been studied in this work. The surface morphology, grain size, surface chemical states, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I–V</i> characteristics, and sensing ability of the films, have been evaluated for postdeposition RTA at different temperatures (400 °C–600 °C) and time (0–60 s). As the annealing temperature was raised, crystallinity improved and the grain size increased. Indeed, XRD revealed that RTA resulted in strong crystallographic orientation in the films. XPS analysis revealed no changes in the oxidation states and chemical composition of the material. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I–V</i> measurements show that the resistance of the film decreases as RTA temperature increases. On the other hand, the sensing characteristics reveal an optimum grain size for the best sensitivity. The films annealed at 500 °C for 60 s, leading to a grain size of about 10 nm, display the highest sensor response of 54%, when exposed to 1000 ppm of CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> .

Effect of rapid thermal annealing on performances of vertical boron-doped diamond Schottky diode with LaB6 interlayer

Effect of rapid thermal annealing on performances of vertical boron-doped diamond Schottky diode with LaB6 interlayer

Large remnant polarization and great reliability characteristics in W/HZO/W ferroelectric capacitors

In this work, the effect of rapid thermal annealing (RTA) temperature on the ferroelectric polarization in zirconium-doped hafnium oxide (HZO) was studied. To maximize remnant polarization (2Pr), in-plane tensile stress was induced by tungsten electrodes under optimal RTA temperatures. We observed an increase in 2Pr with RTA temperature, likely due to an increased proportion of the polar ferroelectric phase in HZO. The HZO capacitors annealed at 400°C did not exhibit any ferroelectric behavior, whereas the HZO capacitors annealed at 800°C became highly leaky and shorted for voltages above 1 V. On the other hand, annealing at 700 °C produced HZO capacitors with a record-high 2Pr of ∼ 64 μC cm−2 at a relatively high frequency of 111 kHz. These ferroelectric capacitors have also demonstrated impressive endurance and retention characteristics, which will greatly benefit neuromorphic computing applications.

Low-Temperature Annealing of CdTe Detectors With Evaporated Gold Contacts and Its Effect on Detector Performance

Cadmium telluride (CdTe) detectors are usually subjected to elevated temperatures during postprocessing and bonding them to readout electronics while fabricating imaging arrays. We studied the effects of low-temperature and short duration rapid thermal annealing of CdTe bulk as well as CdTe epitaxial-layer-based detectors with evaporated gold contacts. The detectors were annealed in the temperature range of 100 °C–300 °C, and its effect on the detector dark current, gamma detection property, and response stability was studied. For the bulk-detectors, the detector dark current decreased and gamma detection properties as well as the performance stability improved after annealing. However, such improvements were moderate for epitaxial-layer-based detectors. The study of the metal–semiconductor interface of annealed detectors revealed that diffused gold, elemental oxygen, and tellurium oxide existed and extended deep inside the bulk portion in epitaxial detectors; however, they were confined in the surface regions only in bulk-detectors, which likely be the causes of observed results in these two types of detectors.